Update integration test Docker image to Alpine 3.6
Update integration test Docker image to Alpine 3.6

RxBroadcast/RxBroadcast,RxBroadcast/RxBroadcast,RxBroadcast/RxBroadcast,whymarrh/RxBroadcast,RxBroadcast/RxBroadcast,whymarrh/RxBroadcast